PRD33Xe0 pages
Differential Pressure Transmitters
Series PRD-33 X
with high overload resistance and line pressure output
The Series PRD-33 X was developed for applications that require a high accuracy differential
pressure measurement together with high overload resistance in differential pressure ranges as
low as 350 mbar.
The Series PRD-33 X is the result of ongoing development of the KELLER PD-33 X differential
pressure transmitter. Thanks to a second integrated pressure sensor, the line, or common mode,
pressure can now be measured along with the differential pressure, resulting in several notable
features not found in traditional differential pressure transmitters.
For example, compensation for line pressure effect is now accomplished during factory
calibration. Moreover, both differential and line (absolute) pressure may be read by the user.
In addition, the PRD-33 X features high differential overload resistance; e.g., ± 35 bar with
a differential measuring range of only 350 mbar (100:1).
The internal differential pressure sensor element is isolated from the High (+) side media by a
compliant stainless steel diaphragm, while the Low (-) side media impinges directly on the back
side of the silicon measuring cell. Also isolated from the High (+) side media is the line (absolute)
pressure sensor. The floating sensor assembly guarantees maximum decoupling from external
mechanical forces.
Another notable feature of the Series PRD-33 X is the robust digital RS485 bi-directional
communication interface. Information such as serial number, pressure range, filter settings and
process values for both differential and line (absolute) pressures and their temperatures are
easily obtained.
This combination of features enables certain measurements not possible with traditional
differential pressure transmitters. For example, filling levels in liquefied gas storage tanks,
including oxygen, nitrogen, carbon dioxide and argon can now be measured safely, accurately
and at reasonable cost.
Features
- High-accuracy differential pressure measurement with compensated line pressure dependency
- Pressure- and temperature-compensated
- Independent line (absolute) pressure output
- High overload resistance
- RS485 communication interface
- Configurable via RS485 interface
- Compact structural design
Applications
- Level measurement of technical gases in liquefied gas tanks
- Differential pressure measurement in case of high unilateral overload resistance
Cable gland
Binder-plug
18,5 mm
M12-plug
18,5 mm
9,5 mm
PIN ASSIGNMENTS
Function
Binder
Serie 723
A-coded
GND
45,5 mm
Cable
white
1
3
M12*
n.c.
G1/4‘‘
1
3
2
blue
4
4
RS485B
yellow
5
5
Shielding
G1/4‘‘
2
black
RS485A
6-KT
SW32
red
Supply
ø 22
Thread
Thread
*t ompatible to CAN wiring components.
C
t Other pin assignments are possible
57 mm
Subject to alterations
KELLER AG für Druckmesstechnikt
KELLER Ges. für Druckmesstechnik mbHt
Companies approved to ISO 9001
11/2013
St. Gallerstrasse 119t
Schwarzwaldstrasse 17t
CH-8404 Winterthurt
D-79798 Jestettent
Tel. +41 (0)52 - 235 25 25t
Tel. +49 (0)7745 - 9214 - 0t
Fax +41 (0)52 - 235 25 00
Fax +49 (0)7745 - 9214 - 60
www.keller-druck.com